The influence of fallback discs on the spectral and timing properties of neutron stars
MetadataShow full item record
Fallback discs around neutron stars (NSs) are believed to be an expected outcome of supernova explosions. Here we investigate the consequences of such a common outcome for the timing and spectral properties of the associated NS population, using Monte Carlo population synthesis models. We find that the long-term torque exerted by the fallback disc can substantially influence the late-time period distribution, but with quantitative differences which depend on whether the initial spin distribution is dominated by slow or fast pulsars. For the latter, a single-peaked initial spin distribution becomes bimodal at later times. Timing ages tend to underestimate the real age of older pulsars, and overestimate the age of younger ones. Braking indices cluster in the range 1.5 ˂ ~n ˂ ~3 for slow-born pulsars, and −0.5 ˂ ~n ˂ ~5 for fast-born pulsars, with the younger objects found predominantly below n ˂ ~ 3. Large values of n, while not common, are possible, and associated with torque transitions in the NS+disc system. The 0.1–10 keV thermal luminosity of the NS+disc system is found to be generally dominated by the disc emission at early times, Graphic yr, but this declines faster than the thermal surface emission of the NS. Depending on the initial parameters, there can be occasional periods in which some NSs switch from the propeller to the accretion phase, increasing their luminosity up to the Eddington limit for ∼103–104 years.
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society, ©: 2012, the authors and the Royal Astronomical Society. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
Showing items related by title, author, creator and subject.
The High Time Resolution Universe Pulsar Survey - VII. Discovery of five millisecond pulsars and the different luminosity properties of binary and isolated recycled pulsarsBurgay, M.; Bailes, M.; Bates, S.; Bhat, Ramesh; Burke-Spolaor, S.; Champion, D.; Coster, P.; D'Amico, N.; johnston, S.; Keith, M.; Kramer, M.; levin, L.; Lyne, A.; Milia, S.; Ng, C.; Possenti, A.; Stappers, B.; Thornton, D.; Tiburzi, C.; van Straten, W.; Bassa, C. (2013)This paper presents the discovery and timing parameters for five millisecond pulsars (MSPs), four in binary systems with probable white dwarf companions and one isolated, found in ongoing processing of the High Time ...
Shannon, Ryan; Johnston, S.; Manchester, R. (2014)We present an analysis of 23 yr of pulse arrival times for PSR B1259−63. The pulsar is in a binary orbit about its approximately 20 M⊙ companion LS 2883. Our best-fitting timing solution has none of the pulse-number ...
Pen, U-l; Macquart, Jean-Pierre; Deller, A; Brisken, W. (2014)We use very long baseline interferometry (VLBI) imaging of the interstellar scattering speckle pattern associated with the pulsar PSR 0834+06 to measure the astrometric motion of its emission. The D ~ 5 au interstellar ...